I bought these a while back on eBay because I wanted to see how they went (to shut someone with a big eco mouth up)
Basically this product reduces the internal volume available in an already small pod.
So for those who fuss and agitation about how bad pods are for the environment you can buy these and pat yourself on the back ... while drinking bad weak coffee.
In terms of the product itself, the pods are well made and of good construction.
However they (being reusable) require you to fish them out of the pod "bin" under the coffee maker to reuse them. In any office situation this will become fraught and for sure someone is going to bin your pod by mistake.
Then you have to ask yourself - how much water are you going to waste in washing them?
If pods bother you so much then either A) get the plastic empty disposable types (which I currently use because I can put my prefered coffee in them) or B) use a proper coffee machine which just grinds and uses the beans (like I do at home).
Pods are generally a bad idea for the sake of convenience - this product take the convenience out of that equation and just makes pods worse.